Combined burglar-alarm and door-fastener



ER. Patented Apr, '5, 1892.

(No Model.)

k G. K. D'ONNELL. COMBINED BURGLAR ALARM AN D DOOR FASTEN W/fA/ESSES: Mz/MMW WWW-V ATTORNEY.

UNITED STATES PATENT OFFICE.

CHARLES K. DONN ELL, OF WEBSTER, MAINE.

COMBINED BURGLAR-ALARM AND DOOR-FASTENER.

SPECIFICATION forming part of Letters Patent No. 472,340, dated April 5, 1892. Application filed November 17, 1890- Serial No. 371,875. (No model.)

To all whom it may concern:

Be it known that 1, CHARLES K. DONNELL, a citizen of the United States, residing at W'ebster, in the county of And'roscoggin and State of Maine, have invented a new and useful Improvement in a Combined Burglar- Alarm and Door-Fastener, of which the following is a specification.

Myinvention relates to that class of bu rglaralarms in which a hook rigidly attached to the shankof the door-knob, a catch entering the crevice of the door, and the frame-work of the alarm coact to prevent the knob from turning far enough to unlatch the door and at the same time permit sufficient motion to release the alarm. Such a combined burglaralarm and door-fastener is fully described in the specification of United States Patent No. 432,987, which was issued to me on the 29th of July, 1890.

The object of my present invention is to provide a device of this sort which shall be more compact and portable and also less expensive in construction and less liable to derangement.

In the accompanying drawings, Figure 1 is a front elevation of the device. Fig. 2 is a similar view of the side next the door. Figs. 3 and 4: are similar sectional end elevations through the line z z of Fig. 2 without the bell. Fig. 3 shows the alarm when set, and Fig. 4 when sprung.

In the drawings, P represents the base-plate of the device. Upon the outer side of this plate is mounted a clock-work alarm covered by a bell, as shown in Fig. 1. The clock-work shown is similar to that used in alarm-clocks, and I do not limit myself to a particular arrangement of it, the most essential feature being that the hammer h should take a position in which it is readily caught and held by the detent m. To the opposite side of the plate P is attached the clamping-piece H, which hooks around the shank of the doorknob and is attached thereto by turning in the set-screw T. This piece H is free to vibrate back and forth in the recess shown'in the supporting-block m. WVhen in the central position shown in Figs. 2 and 3, the piece H covers the detent 0c and holds it against the action of the spring 11. The stud 3 serves to press down the spring at when it is desired to take oif the strain of the spring from the detent w.

W is a box containing the actuating-spring of the alarm.

V is the winding thumb-piece.

The slotted reversible catch K, which enters the crevice between the door and the jamb, is clamped to the base-plate P by the thumb-scew t. WVhen the catch is reversed, the thumb-screw is inserted in the hole (1. By using two holes I am enabled to make the catch much shorter.

When I desire to make use of my device, I first adjust the reversible catch K to fit the door to which it is to be applied. I then press down the spring and its attached detent by means of the stud s and slip the clampingpiece H over the top of the detent to hold it in place. The device is now ready to be applied to the door by hooking the piece H over the door-knob shank and slipping the lip of the catch K between the door and the jamb and afterward clamping the piece H by turning the screw T. The alarm is then wound up by turning the milled head i). If the doorknob is thereafter moved in either direction a sufficient amount, the detent will slip by the piece H and prevent further motion of the door-knob and at the same time permit the alarm to sound until run down.

When I desire to connect the alarm with other doors and windows or with any other movable articles, I attach strings or wires or other flexible connectors to them and to the ring at the lower end of H.

Having now fully described my invention, as the general structure and mode of operation of the device hereinbefore described are similar to my patent No. 432,987, I do not claim them as part of the present invention.

WVhat I claim, and desire to secure by Letters Patent, is-

In a burglar-alarm attached to a door-knob shank, the combination of an alarm mounted upon a base-plate, a releasing-detent which is pressed through a hole in the base-plate by a spring, and a clamping-piece for the shank, which rests upon the top of the detent and keeps it in action while the'shank is at rest, all as set forth.

CHARLES K. DONNELL.

Witnesses:

NOEL B. POTTER, B. F. DONNELL.

IOC 

